Continuously variable electric axles with on-demand energy harvesting capabilities for secondary or tag e-axles

ABSTRACT

Provided herein is an electric powertrain including a differential assembly operably coupled to a drive axle having a set of wheel coupled to the ends thereof; a planetary gear set connected to the differential, the planetary gear set having a sun gear, a planet carrier supporting a plurality of planet gears, and a ring gear, wherein the planet carrier is drivingly engaged with the differential assembly; a first electric motor/generator; a second electric motor/generator; a first gear pass drivingly connected the first electric motor/generator and the ring gear; and a second gear pass drivingly connected the first electric motor/generator and the sun gear.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/487,156, entitled “CONTINOUSLY VARIABLE ELECTRIC AXLES WITH ON-DEMANDENERGY HARVESTING CAPABILITIES FOR SECONDARY OR TAG E-AXLES”, and filedon Aug. 20, 2019. U.S. patent application Ser. No. 16/487,156 is a U.S.National Phase of International Application No. PCT/US2018/019089,entitled “CONTINOUSLY VARIABLE ELECTRIC AXLES WITH ON-DEMAND ENERGYHARVESTING CAPABILITIES FOR SECONDARY OR TAG E-AXLES”, and filed on Feb.22, 2018. International Application No. PCT/US2018/019089 claimspriority to U.S. Provisional Application No. 62/462,117, entitled“CONTINOUSLY VARIABLE ELECTRIC AXLES WITH ON-DEMAND ENERGY HARVESTINGCAPABILITIES FOR SECONDARY OR TAG E-AXLES”, and filed on Feb. 22, 2017.The entire contents of each of the above-listed applications are herebyincorporated by reference for all purposes.

BACKGROUND

Hybrid vehicles are enjoying increased popularity and acceptance due inlarge part to the cost of fuel and greenhouse carbon emission governmentregulations for internal combustion engine vehicles. Such hybridvehicles include both an internal combustion engine a˜ well as anelectric motor to propel the vehicle.

Commercial vehicles or trailers having two or more rear axles allow suchvehicles to carry greater loads when compared to vehicles and trailershaving a single axle. A typical six-wheel drive arrangement for a motorvehicle includes an axle having steerable wheels at the front end of thevehicle and tandem axles at the rear of the vehicle.

Traditional tandem axle drivelines include 6×4 drivelines (i.e., 2wheels on the steer axle and 4 driving wheels on tandem axles behind thesteer axle) or 6×2 drivelines (i.e., 2 wheels on the steer axle and 4wheels on the tandem axles behind the steer axle where only two wheelsare on a drive axle). Any axle in the tandem axles may be a drive axleor a dead axle. When an additional axle (secondary axle) is a dead axle,it may be positioned before (a pusher axle) or after (a tag axle) adrive axle.

It may be useful and advantageous to have an electric tag axle with highreduction capabilities using an existing electric motor that isefficient and compact.

Additionally, it may be beneficial to have an electric driven axle thatcan provide high torque ratios and energy harvesting/energy recuperationabilities.

SUMMARY

Provided herein is an electric powertrain including a differentialassembly operably coupled to a drive axle having a set of wheel coupledto the ends thereof; a planetary gear set connected to the differentialassembly, the planetary gear set having a sun gear, a planet carriersupporting a plurality of planet gears, and a ring gear, wherein theplanet carrier is drivingly engaged with the differential assembly; afirst electric motor/generator; a second electric motor/generator; afirst gear pass drivingly connected the first electric motor/generatorand the ring gear; and a second gear pass drivingly connected the firstelectric motor/generator and the sun gear.

In some embodiments, the first gear pass includes a first portionconnected to a first rotatable shaft and a second portion drivinglyconnected to a second rotatable shaft. In some embodiments, the secondgear pass includes a first portion connected to a third rotatable shaftand a second portion drivingly connected to a fourth rotatable shaft.

In some embodiments, the electric powertrain includes a first reductiongear set positioned between the first electric motor/generator and thefirst gear pass.

In some embodiments, the electric powertrain includes a second reductiongear set positioned between the second electric motor/generator and thesecond gear pass.

In some embodiments, the electric powertrain includes a clutchpositioned between the planet carrier and the differential assembly andconfigured to selectively engage the planet carrier and the differentialassembly.

In some embodiments, the electric powertrain includes a third gear passpositioned between the first gear pass and the first electricmotor/generator, wherein a first portion of the third gear pass isconnected to the second rotatable shaft and a second portion of thethird gear pass drivingly connected to an output shaft of the firstelectric motor/generator.

In some embodiments, the electric powertrain includes a fourth gear passpositioned between the third gear pass and the second electricmotor/generator, wherein a first portion of the fourth gear pass isconnected to the fourth rotatable shaft and a second portion of thefourth gear pass drivingly connected to an output shaft of the secondelectric motor/generator.

In some embodiments, at least one of the gear passes is an epicyclicgear set.

In some embodiments, the electric powertrain includes an over run clutchpositioned between the ring gear and the first gear pass configured toselectively engage the ring gear and the first gear pass.

In some embodiments, the first and second electric motor/generators areparallel to the drive axle.

In some embodiments, the first and second electric motor/generators areaxially adjacent to each other. In some embodiments, the first andsecond rotatable shafts are coaxial with drive axle.

In some embodiments, the electric axle includes a second clutchconnected to a power take off unit and the second electricmotor/generator, wherein the second clutch is configured to selectivelyconnect the power take off unit and the electric powertrain.

BRIEF DESCRIPTION OF THE DRAWINGS

Novel features are set forth with particularity in the appended claims.A better understanding of the features and advantages of the embodimentswill be obtained by reference to the following detailed description thatsets forth illustrative embodiments, in which the principles of theembodiments are utilized, and the accompanying drawings of which:

FIG. 1 is a schematic view of one preferred embodiment of an electricaxle;

FIG. 2 is a schematic view of another preferred embodiment of anelectric axle;

FIG. 3 is a schematic view of another preferred embodiment of anelectric axle;

FIG. 4A is a schematic view of another preferred embodiment of anelectric axle;

FIG. 4B is a schematic view of a tandem axle system including theelectric axle depicted in FIG. 4A;

FIG. 5 is a schematic view of another preferred embodiment of anelectric axle; and

FIG. 6 is a schematic view of another preferred embodiment of anelectric axle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is to be understood that the invention may assume various alternativeorientations and step sequences, except where expressly specified to thecontrary. It is also to be understood that the specific devices andprocesses illustrated in the attached drawings, and described in thefollowing specification are simply exemplary embodiments. Hence,specific dimensions, directions, orientations or other physicalcharacteristics relating to the embodiments disclosed are not to beconsidered as limiting, unless expressly stated otherwise.

Provided herein are electric powertrain configurations that may be usedin hybrid and/or electric vehicles. The powertrains disclosed hereinprovide for an electric axle that provides high torque ratios and energyharvesting/energy recuperation abilities.

In some embodiments, the electric powertrains are part of electric axleswhich are incorporated into vehicles as tag or secondary axles in tandemor multiple axle vehicle systems.

It should be understood that electric or hybrid electric vehiclesincorporating embodiments of the powertrains disclosed herein arecapable of including a number of other additional powertrain components,such as, but not limited to, high-voltage battery pack with a batterymanagement system or ultracapacitor, on-board charger, DC-DC converters,a variety of sensors, actuators, and controllers, among others.

The preferred embodiments will now be described with reference to theaccompanying figures. The terminology used in the descriptions below isnot to be interpreted in any limited or restrictive manner simplybecause it is used in conjunction with detailed descriptions of certainspecific embodiments.

Furthermore, the embodiments include several novel features, no singleone of which is solely responsible for its desirable attributes or whichis essential to practicing the preferred embodiments described.

FIG. 1 is a schematic style view of an electric powertrain 100 accordingto a preferred embodiment. The electric powertrain 100 is amotor/generator driven powertrain, and may be operated in a plurality ofoperating modes.

Referring to FIG. 1, one preferred embodiment of an electric axlepowertrain 100 includes a drivetrain 102 operably coupled to adifferential assembly 104.

In some embodiments, the differential assembly 104 assembly includes acommon differential gear set implemented to transmit rotational power.The differential assembly 104 is operably coupled to a drive axle 106configured to drive a set of wheels 108 a, 108 b on the ends thereof.

The differential assembly 104 is drivingly connected to a firstplanetary gear set 110. The first planetary gear set 110 is providedwith a ring gear 112, a planet carrier 114, and a sun gear 115. Theplanet carrier 114 rotationally supports a plurality of planet gearsthat couple the sun gear 115 to the ring gear 112.

In some embodiments, the differential assembly 104 is coupled directlyto the planet carrier 114.

The ring gear 112 is drivingly connected to a rotatable shaft 116. Shaft116 has a portion of a gear pass (or gear set) 118 drivingly connectedthereto. Gear pass 118 drivingly connects shaft 116 with a rotatableshaft 120. Shaft 120 has a portion of a gear pass 122 (or gear set)drivingly connected thereto. Gear pass 122 drivingly connects shaft 120to an output of a first motor/generator 132.

In some embodiments, shaft 120 extends axially, parallel to the driveaxle 106.

In some embodiments, shaft 120 is perpendicular to the drive axle 106and the gear pass 118 is a right angle ring and pinion gear set.

The sun gear 115 is rotatably connected to a rotatable shaft 124. Shaft124 has a portion of a gear pass 126 (or gear set) drivingly connectedthereto. Gear pass 126 drivingly connects shaft 124 to a rotatable shaft130. Shaft 130 has a portion of a gear pass 128 (or gear set) drivinglyconnected thereto.

In some embodiments, shaft 130 extends axially, parallel to the driveaxle 106. Gear pass 128 drivingly connects shaft 130 to an output of asecond motor/generator 134.

In some embodiments, shaft 124 extends axially, parallel to the driveaxle 106.

In some embodiments, shaft 124 is perpendicular to the drive axle andgear pass 126 is a right angle ring and pinion gear set.

In some embodiments, the motor/generators 132, 134 are capable ofproviding kinetic energy and converting a kinetic energy input to anelectrical energy output (i.e. operate as a motor and a generator). Forexample, when the operator of the vehicle depresses the brake pedal thegenerator can covert the kinetic energy into electrical energy (i.e.regenerative braking).

In some embodiments, the motor/generators 132, 134 are connected to anenergy storage device. The energy storage device can be a battery havinga battery pack or a capacitor; however, it is understood that otherembodiments may include other power sources including electrochemicalenergy conversion devices or combinations thereof including, but notlimited to, an ultracapicitor or a fuel cell particularly in a fuel cellelectric vehicle drivetrains (FCEV).

In some embodiments, the powertrain 100 is provided in a tag orsecondary axle of a tandem axle or multi-axle system.

In some embodiments, the first and second motor/generators 132, 134 arepositioned on radially opposite sides of the drive axle 106.

In some embodiments, at least one of gear passes 118, 122, 126 or 128are a step gear set or an epicyclic gear set.

In some embodiments, the first motor/generator 132 is perpendicular tothe drive axle 106 and one of gear pass 122 or gear pass 118 is a rightangle ring and pinion gear set.

In some embodiments, the second motor/generator 134 is perpendicular tothe drive axle 106 and one of gear pass 128 or gear pass 126 is a rightangle ring and pinion gear set.

In some embodiments, at least one of gear passes 118, 122, 126 or 128are step gears or epicyclic gears.

The planetary gear set 110 may function as a power summation point or apower split point depending on the mode of operation of the powertrain100. The planetary gear set 110 functions as a power summation point ofpower from the motor/generators 132, 134 when power flows to the wheels108 a, 108 b and as a power split when the motor/generators 132, 134function as generators. When the power flow comes from the wheels 108 a,108 b, the planetary gear set 110 splits power at the carrier 114 andthe kinetic energy 20 provided can be recuperated by themotor/generator(s) 132, 134.

For any given wheel speed the first motor/generator 132 (oralternatively the second motor/generator 134) can operate as a motorproviding power to the powertrain 100 and the second motor/generator 134(or alternatively the second motor/generator 132) can operate as agenerator. The generator 134 can maintain the state of charge in thebattery pack or level of energy stored in the energy storage device at asustainable or threshold level. By doing so, the energy storage deviceis able to provide the powertrain 100 energy for on-demand boosting ifdesired. If both the first and second motor/generators 132, 134 areoperating as generators, the powertrain 100 provides a higher energyrecuperation.

The motor 132 and generator 134 can operate at independent speeds due tothe presence of the planetary gear set 110 which splits the power fromthe wheels with the differential assembly 104 connected to the carrier114. The motor/generator 132, 134 speeds are not limited to the wheel108 a, 108 b speeds providing greater efficiency to the powertrain 100.

The electric powertrain 100 can operate in multiple modes of operationproviding a change in speed ratio from high to low continuously bycontrolling the speed of the first motor/generator 132 providing of acontinuously variable electric variable axle.

In some embodiments, all components of the powertrain 100 are under thesupervisory control of a vehicle system controller (VSC) not shown. Eachpowertrain component can have a separate controller under thesupervisory control of the VSC.

In some embodiments, the powertrain 100 includes a separate batterycontroller (not shown) as part of a battery management system (notshown).

In some embodiments, the controller and/or VSC is configured to receivea number of electronic signals from sensors provided on the powertrain,vehicle, wheels, etc. The sensors optionally include temperaturesensors, speed sensors, position sensors, among others.

In some embodiments, the controller and the VSC are configured toperform routines such as signal acquisition, signal arbitration, orother known methods for signal processing and is configured toelectronically communicate to a variety of actuators and sensors.

FIG. 2 depicts another preferred embodiment an electric powertrain 200.The embodiment shown in FIG. 2 includes similar components to thepowertrain 100. Similar features of the embodiment shown in FIG. 2 arenumbered similarly in series. Different and additional features of thevariation shown in FIG. 2 are described hereinbelow and can beappreciated by one skilled in the art in view of FIG. 1 and the otherembodiments illustrated and described in this disclosure.

The electric axle powertrain 200 includes a drivetrain 202 operablycoupled to a differential assembly 204.

In some embodiments, the differential assembly 204 includes a commondifferential gear set implemented to transmit rotational power.

The differential assembly 204 is operably coupled to a drive axle 206configured to drive a set of vehicle wheels 208 a, 208 b on the endsthereof. The differential assembly 204 is drivingly connected to a firstplanetary gear set 210. The first planetary gear set 210 is providedwith a ring gear 212, a planet carrier 214, and a sun gear 215. Theplanet carrier 214 rotationally supports a plurality of planet gearsthat couple the sun gear 215 to the ring gear 212. The ring gear 212 isdrivingly connected to a rotatable shaft 216. Shaft 216 has a 10 portionof a gear pass 218 drivingly connected thereto. Gear pass 218 drivinglyconnects shaft 216 with a rotatable shaft 220. Shaft 220 has a portionof a gear pass 222 drivingly connected thereto.

In some embodiments, the differential assembly 204 is coupled to theplanet carrier 214.

In some embodiments, shaft 220 extends axially, parallel to the driveaxle 206.

In some embodiments, shaft 220 is perpendicular to the drive axle 206and the gear pass 218 is a right angle ring and pinion gear set.

Gear pass 222 drivingly connects shaft 220 to a reduction unit 221including a reducing gear set 223 drivingly connected to an output of afirst motor/generator 232. The sun gear 215 is rotatably connected to arotatable shaft 224.

In some embodiments, shaft 224 extends axially, parallel to the driveaxle 206.

Shaft 224 has a portion of a gear pass 226 drivingly connected thereto.Gear pass 226 drivingly connects shaft 224 to a rotatable shaft 230.Shaft 230 has a portion of a gear pass 228 drivingly connected thereto.Gear pass 228 drivingly connects shaft 230 to a reduction unit 231including a reducing gear set 233 drivingly connected to an output of asecond motor/generator 234.

In some embodiments, the first and second motor/generators 232, 234 arepositioned parallel to the drive axle 206.

In some embodiments, at least one of gear passes 218, 222, 226 or 228are a step gear set or an epicyclic gear set.

In some embodiments, the first motor/generator 234 is perpendicular tothe drive axle 206 and one of gear pass 222 or gear pass 218 is a rightangle ring and pinion gear set.

In some embodiments, the second motor/generator 234 is perpendicular tothe drive axle 206 and one of gear pass 228 or gear pass 226 is a rightangle ring and pinion gear set.

As shown in FIG. 2, in some embodiments, the reducing gear set 223,233are planetary gear sets that provide a primary gear reduction.

By providing an initial gear reduction, the planetary gear set 210 canhave lower gear ratios and the gear passes 218, 222, 226, 228 includesmall diameter gears reducing the overall number of gear passes andthereby reducing the drivetrain packaging requirements.

In some embodiments, the reducing planetary gear sets 223, 233 caninclude a sun gear, a ring gear, and a plurality of compound planetgears rotatably mounted to a planet carrier. The sun gear can beintegrally formed at one of the output shaft of the motor/generator 232,234. The ring gear is fixed to a stationary member or housing assembly.The planet carrier is drivingly connected to gear pass 222.

In some embodiments, the reducing gear sets 223, 233 are coaxial withthe outputs of the motor/generators 232, 234.

FIG. 3 depicts another preferred embodiment of an electric powertrain300. The embodiment shown in FIG. 3 includes similar components to thepowertrain 100. Similar features of the embodiment shown in FIG. 3 arenumbered similarly in series. Different and additional features of thevariation shown in FIG. 3 are described hereinbelow and can beappreciated by one skilled in the art in view of FIG. 1 and the otherembodiments illustrated and described in this disclosure.

The electric axle powertrain 300 includes a drivetrain 302 operablycoupled to a differential assembly 304.

In some embodiments, the differential assembly 304 includes a commondifferential gear set implemented to transmit rotational power. Thedifferential assembly 304 is operably coupled to a drive axle 306configured to drive a set of vehicle wheels 308 a, 308 b on the endsthereof.

The differential assembly 304 is drivingly connected to a firstplanetary gear set 310. The first planetary gear set 310 is providedwith a ring gear 312, a planet carrier 314, and a sun gear 315. Theplanet carrier 314 rotationally supports a plurality of planet gearsthat couple the sun gear 315 to the ring gear 312.

In some embodiments, the differential assembly 304 is coupled to theplanet carrier 312.

The ring gear 312 is drivingly connected to a rotatable shaft 316. Shaft316 has a portion of a gear pass 318 drivingly connected thereto. Gearpass 318 drivingly connects shaft 316 with a rotatable shaft 320. Shaft320 has a portion of a gear pass 322 drivingly connected thereto.

In some embodiments, shaft 320 extends axially, parallel to the driveaxle 306. Gear pass 322 drivingly connects shaft 320 to an output of afirst motor/generator 332.

The sun gear 315 is rotatably connected to a rotatable shaft 324. Shaft324 is drivingly connected to an output of a second motor/generator 334.

In some embodiments, shaft 324 extends axially, parallel to the driveaxle 306.

In some embodiments, the first and second motor/generators 332, 334 areaxially adjacent to each other and the rotatable shafts 316 and 320 arecoaxial with the drive axle 306.

In some embodiments, the output shafts of the first motor/generator andthe second motor/generator are concentric.

In some embodiments, shaft 320 is transfer to the output shafts of thefirst and second motor/generators.

In some embodiments, at least one of gear passes 318, 322, 326 or 328 isa step gear set or an epicyclic gear set.

FIG. 4A depicts another preferred embodiment an electric powertrain 400.The embodiment shown in FIG. 4A includes similar components to thepowertrain 100. Similar features of the embodiment shown in FIG. 4A arenumbered similarly in series. Different and additional features of thevariation shown in FIG. 4A are described hereinbelow and can beappreciated by one skilled in the art in view of FIG. 1 and the otherembodiments illustrated and described in this disclosure.

The electric axle powertrain 400 includes a drivetrain 402 operablycoupled to a differential assembly 404. The differential assembly 404 isoperably coupled to a drive axle 406 configured to drive a set ofvehicle wheels 408 a, 408 b on the ends thereof.

In some embodiments, the differential assembly 404 includes a commondifferential gear set implemented to transmit rotational power.

The differential assembly 404 is drivingly connected to a firstplanetary gear set 410. The first planetary gear set 410 is providedwith a ring gear 412, a planet carrier 414, and a sun gear 415. The ringgear 412 is drivingly connected to a rotatable shaft 416. Shaft 416 hasa portion of a gear pass 418 drivingly connected thereto. Gear pass 418drivingly connects shaft 416 with a rotatable shaft 420. Shaft 420 has aportion of a gear pass 422 drivingly connected thereto. Gear pass 422drivingly connects shaft 420 to an output of a first motor/generator432.

In some embodiments, the differential assembly 404 is coupled to theplanet carrier 414.

The sun gear 415 is rotatably connected to a rotatable shaft 424. Shaft424 has a portion of a gear pass 426 drivingly connected thereto. Gearpass 426 drivingly connects shaft 424 to a rotatable shaft 430. Shaft430 has a portion of a gear pass 428 drivingly connected thereto. Gearpass 428 drivingly connects shaft 430 to an output of a secondmotor/generator 434.

In some embodiments, shaft 424 extends axially, parallel to the driveaxle 406.

In some embodiments, the first and second motor/generators 432, 434 arepositioned parallel to the drive axle 406.

In some embodiments, at least one of gear passes 418, 422, 426 or 428 isa step gear set or an epicyclic gear set.

In some embodiments, the first motor/generator 432 is perpendicular tothe drive axle 406 and one of gear pass 422 or gear pass 418 is a rightangle ring and pinion gear set.

In some embodiments, the second motor/generator 434 is perpendicular tothe drive axle 406 and one of gear pass 428 or gear pass 426 is a rightangle ring and pinion gear set.

In some embodiments, the drivetrain 410 includes a clutch 440 thatselectively connects the second motor/generator 434 to a drive shaft.The clutch 440 is in communication with the controller.

In some embodiments, the clutch 440 is connected to a power take off 15unit 442.

FIG. 4B depicts the location of the clutch 440 in a tandem axle system450 having an electric tag axle 452, a driven axle 454 and a PTO device442. By connecting the drive axle 454 to a drive shaft, the drive axle454 has electrically continuously variable functionality. If the clutch440 is engaged, then the axle 454 becomes a dedicated hybrid transaxle.

When the system 450 is connected to an internal combustion engine orother power source, when clutch 440 is engaged power from the internalcombustion engine us added to the power supplied by the motor/generator434 and motor/generator 432 functions as a generator.

In some embodiments, clutch 440 is a dog clutch, clone clutch, wetclutch or dry clutch.

In some embodiments, clutch 440 is a hydraulically actuated wet clutchpack.

In some embodiments, a second disconnect clutch 444 is added to one ofthe wheels of the tag axle 452. The electric tag axle 452 can be used toexport power to a grid for a plug-in hybrid vehicle embodiment which hasan onboard charger. In some embodiments, the vehicle includes anauxiliary power unit powered by the electric tag axle 452 when thevehicle is stationary and can include exportable power to gridconfigurations.

FIG. 5 depicts another preferred embodiment an electric powertrain 500.The embodiment shown in FIG. 5 includes similar 5 components to thepowertrain 100. Similar features of the embodiment shown in FIG. 5 arenumbered similarly in series. Different and additional features of thevariation shown in FIG. 5 are described hereinbelow and can beappreciated by one skilled in the art in view of FIG. 1 and the otherembodiments illustrated and described in this disclosure.

The electric powertrain 500 includes a drivetrain 502 operably coupledto a differential assembly 504.

In some embodiments, the differential assembly 504 includes a commondifferential gear set implemented to transmit rotational power.

The differential assembly 504 is operably coupled to a drive axle 506configured to drive a set of vehicle wheels 508 a, 508 b on the endsthereof. The differential assembly 504 is drivingly connected to a firstplanetary gear set 510. The first planetary gear set 510 is providedwith a ring gear 512, a planet carrier 514, and a sun gear 515.

In some embodiments, the differential assembly 504 is selectivelydrivingly coupled to the planet carrier 514.

A clutch 517 is positioned between the planet carrier 514 and thedifferential assembly 504 to selectively couple the differentialassembly 504 to the carrier 514. When the clutch 517 is disengaged, thedifferential assembly 504 runs in a neutral mode minimizing drag lossesby disengaging the powertrain from the differential assembly 504.

In some embodiments, the ring gear 512 is drivingly connected to an overrun clutch 519. The over-run clutch 519 is drivingly connected to thering gear 512 and a shaft 516.

Shaft 516 has a portion of a gear pass 518 drivingly connected thereto.Gear pass 518 drivingly connects shaft 516 with a rotatable shaft 520.Shaft 520 has a portion of a gear pass 522 drivingly connected thereto.Gear pass 522 drivingly connects shaft 520 to an output of a firstmotor/generator 532.

The sun gear 515 is rotatable connected to a rotatable shaft 524. Shaft524 has a portion of a gear pass 526 drivingly connected thereto. Gearpass 5 526 drivingly connects shaft 524 to a rotabable shaft 530. Shaft530 has a portion of a gear pass 528 drivingly connected thereto. Gearpass 528 drivingly connects shaft 530 to an output of a secondmotor/generator 534. In some embodiments, shaft 524 extends axially,parallel to the drive axle 506.

In some embodiments, the first and second motor/generators 532, 534 arepositioned on parallel to the drive axle 506.

In some embodiments, the first motor/generator 532 is perpendicular tothe drive axle 506 and one of gear pass 522 or gear pass 518 is a rightangle ring and pinion gear set.

In some embodiments, at least one of gear passes 518, 522, 526 or 528 15is a step gear set or an epicyclic gear set.

In some embodiments, the second motor/generator 534 is perpendicular tothe drive axle 506 and one of gear pass 528 or gear pass 526 is a rightangle ring and pinion gear set.

The over-run clutch 519 prevents the motor/generator 532 from being backdriven by the powertrain 500. The ring gear 512 of the planetary gearset 510 can experience higher torque than the sun gear 515 because ofthe ring-to-sun (RTS) ratio. If the motor/generator 532 cannot produceenough torque such that torque on the ring gear 512 is not equal to thetorque on the sun gear 515 multiplied by the RTS ratio, the ring gear512 is back driven. The over-run clutch 519 is placed along themotor/generator 532 to ring gear 512 power path to prevent the ring gear512 from back rotating.

In some embodiments, the over-run clutch 519 is a directional over runclutch. The directional over run clutch 519, when energized, allows themotor/generator 532 to reverse the rotation of the output of themotor/generator 532 rotate as needed such as when the motor/generator532 is operating in a regeneration mode.

A controller can control the operating mode of the powertrain 500 by atleast by controlling the engagement of the over-run clutch 519 andclutch 517. In response to a signal sent by the controller, an actuatorcan engage the over-run clutch 519 and/or the clutch 517.

FIG. 6 depicts another preferred embodiment of an electric powertrain600. The embodiment shown in FIG. 6 includes similar components to thepowertrain 100. Similar features of the embodiment shown in FIG. 6 arenumbered similarly in series. Different and additional features of thevariation shown in FIG. 6 are described hereinbelow and can beappreciated by one skilled in the art in view of FIG. 1 and the otherembodiments illustrated and described in this disclosure.

The electric powertrain 600 includes a drivetrain 602 operably coupledto a differential assembly 604. The differential assembly 604 isoperably coupled to a drive axle 606 configured to drive a set ofvehicle wheels 608 a, 608 b on the ends thereof. The differentialassembly 604 is drivingly connected to a first planetary gear set 610.The first planetary gear set 610 is provided with a ring gear 612, aplanet carrier 614, and a sun gear 614.

In some embodiments, the differential assembly 604 includes a commondifferential gear set implemented to transmit rotational power.

In some embodiments, the differential assembly 604 is drivingly coupledto the planet carrier 614.

The ring gear 612 is drivingly connected to a rotating shaft 616. Shaft616 has a portion of a gear pass 618 drivingly connected thereto. Gearpass 618 selectively drivingly connects shaft 616 with a rotatable shaft620. Shaft 616 has a portion of a gear pass 622 drivingly connectedthereto. Gear pass 622 selectively drivingly connects shaft 616 withshaft 620. Shaft 620 is drivingly attached to an output of a firstmotor/generator 632. The sun gear 615 is rotatably connected to arotatable shaft 624.

Shaft 624 has a portion of a gear pass 626 drivingly connected thereto.Gear pass 626 selectively drivingly connects shaft 624 to a rotatableshaft 630. Shaft 630 has a portion of a gear pass 628 drivinglyconnected thereto. Gear pass 628 selectively drivingly connects shaft630 to shaft 624. Shaft 630 is drivingly attached to an output of asecond motor/generator 634.

In some embodiments, shaft 624 extends axially, parallel to the driveaxle 606.

In some embodiments, the first and second motor/generators 632, 634 arepositioned parallel to the drive axle 606.

In some embodiments, the first motor/generator 632 is perpendicular tothe drive axle and one of gear pass 622 or gear pass 618 is a rightangle ring and pinion gear set.

In some embodiments, at least one of gear passes 618, 622, 626 or 628 isa step gear set or an epicyclic gear set.

In some embodiments, the second motor/generator 634 is perpendicular tothe drive axle 606 and one of gear pass 628 or gear pass 626 is a rightangle ring and pinion gear set.

The powertrain 600 is configured to be placed in at least two modes ofoperation, depending on a position of a selector sleeve 633. In a firstmode of operation, the powertrain 600 operates in a low speed modeoperation. In a second mode of operation, the powertrain 600 operates ina high speed mode operation.

A controller can control the operating mode of the powertrain 600 by atleast by adjusting a position of the selector sleeve 633. To switchbetween the modes of operation, a selector sleeve 633 engage shafts 620with either gear pass 622 and 618 by means of a clutching action. Ashift fork 635 disposed in an annular recess formed in the selectorsleeve 633 moves the selector sleeve 633 along the axis of shaft 620into a first position, a second position, or a neutral position. Inresponse to a signal sent by the controller, an actuator adjusts aposition of the selector sleeve 633.

In the first position or low mode of operation, the selector sleeve 633is drivingly engaged with the gear pass 622 and shaft 620. The power istransferred from the motor/generator 632 through the selector spline togear pass 622 to shaft 616 through the planetary gear set 610 to thedifferential assembly 604 and, thus, to the wheels 608 a, 608 b throughthe drive axle 606.

In the second position or high speed mode of operation, the selectorsleeve 633 is drivingly engaged with gear pass 618 and shaft 620. Thepower is transferred from the motor/generator 632 through the selectorspline to gear pass 618, to shaft 616 through the planetary gear set 610to the differential assembly 604 and, thus, to the wheels 608 a, 608 bthrough the drive axle 606.

In the neutral position, the selector sleeve 633 engages neither gearpass 622 or gear pass 618, the selector sleeve 633 is in a neutralposition.

The powertrain 600 is configured to be placed in multiple modes ofoperation, depending on a position of a selector sleeve 637. In a firstmode of operation, the powertrain 600 operates in a high speed modeoperation. In a second mode of operation, the powertrain 600 operates ina low speed mode operation. In the high and low modes of operation theratios are continuously variable within a range determined by the ratiosof the gear passes and planetary gear set.

Similarly, the controller can control the operating mode of thepowertrain 600 by at least by adjusting a position of the selectorsleeve 637. To switch between the modes of operation, a selector sleeve637 engage shaft 630 with either gear pass 626 and 628 by means of aclutching action. A shift fork 639 disposed in an annular recess formedin the selector sleeve 637 moves the selector sleeve 637 along the axisof shaft 630 into a first position, a second position, or a neutralposition. In response to a signal sent by the controller, an actuatoradjusts a position of the selector sleeve 637.

In the first position or low mode of operation, the selector sleeve 637is drivingly engaged with the gear pass 626 and shaft 630. The power istransferred from the motor/generator 634 through the selector spline togear pass 626 to shaft 624 through the planetary gear set 610 to thedifferential assembly 604 and, thus, to the wheels 608 a, 608 b throughthe drive axle 606.

In the second position or high speed mode of operation, the selectorsleeve 637 is drivingly engaged with gear pass 628 and shaft 630. Thepower is transferred from the motor/generator 634 through the selectorspline to gear pass 628, to shaft 624 through the planetary gear set 610to the differential assembly 604 and, thus, to the wheels 608 a, 608 bthrough the drive axle 606.

In the neutral position, the selector sleeve 637 engages neither gearpass 626 or gear pass 628, the selector sleeve 637 is in a neutralposition.

It is understood the selector sleeves 633,637 and shift forks 635, 639may be substituted with any clutching device that permits selectiveengagement of a driving and a driven part. In some embodiments, a clutchcan be used instead of the shift fork. The clutch can be, but is notlimited to, a dog clutch, a clone clutch, a wet or dry clutch includinga hydraulically actuated wet clutch pack. If a low speed range isdesired the selector spline is engaged with gear pass 622. The power istransferred from the motor/generator 632 through the selector spline togear pass 622, to shaft 616 through the planetary gear set 610 to thedifferential assembly 604 and, thus, to the wheels 608 a, 608 b throughthe drive axle 606.

If a high speed range is desired the selector spline is engaged withgear pass 618. The power is transferred from the motor/generator 632through the selector spline to gear pass 618, to shaft 616 through theplanetary gear set 610 to the differential assembly 604 and, thus, tothe wheels 608 a, 608 b through the drive axle 606. When neither gearpass 622 nor gear pass 618 is engaged, the selector sleeve 637 is in aneutral position.

In some embodiments, an over run clutch (not shown) prevents themotor/generator 632 from being back driven by the powertrain 600. Thering gear 612 of the planetary gear set 610 can experience higher torquethan the sun gear 615 because of the ring-to-sun (RTS) ratio. If themotor/generator 632 cannot produce enough torque such that torque on thering gear 612 is not equal to the torque on the sun gear 615 multipliedby the RTS ratio, the ring gear 612 is back driven. The over-run clutch619 is placed along the motor/generator 632 to ring gear 612 power pathto prevent the ring gear 614 from back rotating.

It should further be noted that the electric powertrains disclosedherein are optionally used as primary drive axles, second drive axles,or both.

It should be understood that each gear pass can include multiple gearsincluding planetary gears. In some embodiments, at least one of the gearpasses is a planetary gear set having a sun gear, ring gear and aplurality of planet gears supported by a planet carrier wherein one ofthe sun gear, ring rear or planet carrier can be grounded to astationary member or housing.

It should be understood that additional clutches/brakes, step ratios areoptionally provided to the hybrid powertrains disclosed herein to obtainvarying power path characteristics. It should be noted that theconnections of the electric machines to the power paths disclosed hereinare provided for illustrative example and it is within a designer'smeans to couple the electric machines to other components of thepowertrains disclosed herein.

It should be noted that the battery is capable of being not just a highvoltage pack such as lithium ion or lead-acid batteries, but alsoultracapacitors or other pneumatic/hydraulic systems such asaccumulators, or other forms of energy storage systems.

The motor/generators described herein are capable of representinghydromotors actuated by variable displacement pumps, electric machines,pneumatic motors driven by pneumatic pumps, etc.

While the preferred embodiments have been shown and described herein, itwill be obvious to those skilled in the art that such embodiments areprovided by way of example only. Numerous variations, changes, andsubstitutions will now occur to those skilled in the art withoutdeparting from the embodiments. It should be understood that variousalternatives to the embodiments described herein are capable of beingemployed in practicing the embodiments.

Various embodiments as described herein are provided in the Aspectsbelow:

Aspect 1. An electric powertrain comprising: a differential assemblyoperably coupled to a drive axle having a set of wheels coupled to theends thereof; a planetary gear set connected to the differentialassembly, the planetary gear set having a sun gear, a planet carriersupporting a plurality of planet gears, and a ring gear, wherein theplanet carrier is drivingly engaged with the differential assembly; afirst electric motor/generator; a second electric motor/generator; afirst gear pass drivingly connected to the first electricmotor/generator and the ring gear; and a second gear pass drivinglyconnected to the first electric motor/generator and the sun gear.

Aspect 2. The electric powertrain of Aspect 1, wherein a first portionof the first gear pass is connected to a first rotatable shaft and asecond portion of the first gear pass is drivingly connected to a secondrotatable shaft.

Aspect 3. The electric powertrain of one of Aspects 1-2, wherein a firstportion of the second gear pass is connected to a third rotatable shaftand a second portion of the second gear pass drivingly connected to afourth rotatable shaft.

Aspect 4. The electric powertrain of one of Aspects 1-3 furthercomprising a first reduction gear set positioned between the firstelectric motor/generator and the first gear pass.

Aspect 5. The electric powertrain of one of Aspects 1-4 furthercomprising a second reduction gear set positioned between the secondelectric motor/generator and the second gear pass.

Aspect 6. The electric powertrain of one of Aspects 1-5 furthercomprising a clutch positioned between the planet carrier and thedifferential assembly, wherein the clutch is configured to selectivelyengage the planet carrier and the differential assembly.

Aspect 7. The electric powertrain of one of Aspects 1-6 furthercomprising a third gear pass positioned between the first gear pass andthe first electric motor/generator, wherein a first portion of the thirdgear pass is connected to the second rotatable shaft and a secondportion of the third gear pass drivingly connected to an output shaft ofthe first electric motor/generator.

Aspect 8. The electric powertrain of one of Aspects 1-7 furthercomprising a fourth gear pass positioned between the third gear pass andthe second electric motor/generator, wherein a first portion of thefourth gear pass is connected to the fourth rotatable shaft and a secondportion of the fourth gear pass drivingly connected to an output shaftof the second electric motor/generator.

Aspect 9. The electric powertrain of one of Aspects 1-8, wherein atleast one of the gear passes is an epicyclic gear set.

Aspect 10. The electric powertrain of one of Aspects 1-9 furthercomprising an over run clutch positioned between the ring gear and thefirst gear pass, wherein the over-run clutch is configured toselectively engage the ring gear and the first gear pass.

Aspect 11. The electric powertrain of one of Aspects 1-10, wherein thefirst and second electric motor/generators are parallel to the driveaxle.

Aspect 12. The electric powertrain of one of Aspects 1-11, wherein thefirst and second electric motor/generators are axially adjacent to eachother.

Aspect 13. The electric power train of one of Aspects 1-12, wherein thefirst and second rotatable shafts are coaxial with drive axle.

Aspect 14. An electric axle comprising the electric powertrain of one ofAspects 1-13.

Aspect 15. The electric axle of Aspect 14 further comprising a secondclutch connected to a power take off unit and the second electricmotor/generator, wherein the second clutch is configured to selectivelyconnect the power take off unit and the electric powertrain.

What is claimed:
 1. An axle assembly, comprising: a firstmotor/generator connected to a first output shaft; a secondmotor/generator connected a second output shaft; a differential assemblycoupled to a drive axle a first gear set having a first gear and asecond gear, the first gear of the first gear set connected to the firstoutput shaft; a first rotatable shaft, the second gear of the first gearset connected to the first rotatable shaft; a second gear set having afirst gear and a second gear, the second gear connected to the firstrotatable shaft; a second rotatable shaft, the second gear set connectedto the second rotatable shaft; and a first planetary gear set having afirst ring gear, a first planet carrier, and a first sun gear; the firstring gear of the first planetary gear set connected to the secondrotatable shaft, the first planetary gear set connected to thedifferential assembly.
 2. The axle assembly of claim 1, furthercomprising a third gear set having a first gear and a second gear, thefirst gear of the third gear set connected to the second output shaft;and a third rotatable shaft, the second gear of the third gear setconnected to the third rotatable shaft.
 3. The axle assembly of claim 2,further comprising: a fourth gear set having a first gear and a secondgear, the first gear of the fourth gear connected to the third rotatableshaft; a fourth rotatable shaft extending co-axially the secondrotatable shaft and the drive axle, the second gear of the fourth gearset connected to the fourth rotatable shaft; and wherein the first sungear of the first planetary gear set is connected to the fourthrotatable shaft.
 4. The axle assembly of claim 3, wherein the secondrotatable shaft is connected to the fourth rotatable shaft and the driveaxle.
 5. The axle assembly of claim 3, wherein the fourth rotatableshaft is connected to the drive axle.
 6. The axle assembly of claim 1,further comprising a first reduction gear set connecting the firstmotor/generator to the first gear set.
 7. The axle assembly of claim 2,further comprising a second reduction gear set connecting the secondmotor/generator to the third gear set.
 8. The axle assembly of claim 1,further comprising a clutch connecting the second motor/generator to adrive shaft connected to the drive axle.
 9. The axle assembly of claim1, further comprising an over-run clutch connecting the second rotatableshaft to the first ring gear of the first planetary gear set, and theover-run clutch preventing the first motor/generator from being backdriven.
 10. The axle assembly of claim 1, further comprising a clutchconnecting the first planetary gear set to the differential assembly.11. An axle assembly, comprising: a first motor/generator connected to afirst output shaft; a second motor/generator connected a second outputshaft; a differential assembly coupled to a drive axle a first gear sethaving a first gear and a second gear, the first gear of the first gearset connected to the first output shaft; a first rotatable shaft, thesecond gear of the first gear set connected to the first rotatableshaft; a second gear set having a first gear and a second gear, thesecond gear connected to the first rotatable shaft; a second rotatableshaft, the second gear set connected to the second rotatable shaft, andthe second rotatable shaft extending co-axially with the drive axle; afirst planetary gear set having a first ring gear, a first planetcarrier, and a first sun gear; the first ring gear of the firstplanetary gear set connected to the second rotatable shaft, the firstplanetary gear set connected to the differential assembly; and thesecond output shaft extending co-axially with the drive axle, the firstoutput shaft, and the second rotatable shaft, and the second outputshaft connected to the first sun gear of the first planetary gear set.12. The axle assembly of claim 11, wherein the first motor/generator andthe second motor/generator are directly axially adjacent to each other.13. The axle assembly of claim 11, wherein the first output shaft isconnected to the drive axle and the second output shaft.
 14. The axleassembly of claim 11, wherein the second rotatable shaft is connected tothe drive axle and the second output shaft.
 15. An axle assembly,comprising: a first motor/generator connected to a first output shaft; adifferential assembly coupled to a drive axle a first gear set having afirst gear and a second gear, the first gear of the first gear setconnected to the first output shaft; a first rotatable shaft, the secondgear of the first gear set connected to the first rotatable shaft; asecond gear set having a first gear and a second gear, the second gearconnected to the first rotatable shaft; a second rotatable shaft, thesecond gear set connected to the second rotatable shaft; and a firstplanetary gear set having a first ring gear, a first planet carrier, anda first sun gear; the first ring gear of the first planetary gear setconnected to the second rotatable shaft, the first planetary gear setconnected to the differential assembly a second motor/generatordrivingly connected to a third rotatable shaft; a third gear set havinga first gear and a second gear; a fourth gear set having a first gearand a second gear; and the first gear of the third gear pass and thefirst gear of the fourth gear pass extend co-axially with the thirdrotatable shaft.
 16. The axle assembly of claim 15, wherein the firstgear of the first gear set and the first gear of the second gear setextend co-axially with the first rotatable shaft; and the secondrotatable shaft extends co-axially with the drive axle.
 17. The axleassembly of claim 15, further comprising a fourth rotatable shaft;wherein the second gear of the third gear set and the second gear of thefourth gear set are connected to the fourth rotatable shaft; wherein thesecond gear of the third gear set, the second gear of the fourth gearset, and the first sun gear of the first planetary gear set areconnected the fourth rotatable shaft; wherein the fourth rotatable shaftextends co-axially with the drive axle and the second rotatable shaft.18. The axle assembly of claim 15, further comprising: a first selectorsleeve with a first position and a second position; wherein in the firstposition the first selector sleeve connects a plurality of splines onthe first rotatable shaft with a plurality of splines on the first gearof the first gear set, wherein in the second position the first selectorsleeve connects the plurality of splines on the first rotatable shaftwith a plurality of splines on the first gear of the second gear set.19. The axle assembly of claim 15, further comprising: a second selectorsleeve with a first position and a second position; wherein in the firstposition, the second selector sleeve connects a plurality of splines onthe third rotatable shaft with a plurality of splines on the first gearof the third gear set, and wherein in the second position, the secondselector sleeve connects the plurality of splines on the third rotatableshaft with a plurality of splines on the first gear of the fourth gearset.
 20. The axle assembly of claim 17, wherein the fourth rotatableshaft has a hollow portion which receives the drive axle.